Blog · Scanning
How accurate are iPhone room scans?
Accurate enough for floor plans, layouts and quotes. Apple publishes no official tolerance for RoomPlan scans. A peer-reviewed test of iPhone 12 Pro and iPad Pro LiDAR measured about ±1 cm on objects larger than 10 cm. Glass, mirrors, clutter and very large rooms reduce accuracy, so check one or two key walls with a tape before ordering anything cut to size.
What the research says
| Source | What was measured | Result |
|---|---|---|
| Apple Machine Learning Research (2022) | How reliably RoomPlan detects walls, windows and doors | About 95% precision and recall for walls and windows, 90% for doors. Supports rooms up to 15 x 15 m and 3.6 m high; Apple recommends scanning areas up to about 9 x 9 m. |
| Luetzenburg, Kroon and Bjørk, Scientific Reports (2021) | 3D models from iPhone 12 Pro and iPad Pro LiDAR | About ±1 cm on objects with sides over 10 cm. About ±10 cm across a 130 m long outdoor cliff. |
| Spreafico et al., ISPRS Archives (2021) | iPad Pro LiDAR for building surveys | Point clouds suitable for 1:200 scale architectural mapping. |
Apple's figures describe whether a wall or door is found, not how many centimetres it is off by, and the Scientific Reports figures are for 3D models of objects and terrain rather than a finished floor plan. We found no peer-reviewed study that gives a centimetre tolerance for RoomPlan floor plans, and figures you see quoted online without a source should be treated with care.
Where scans go wrong
- Glass, mirrors and shiny floors reflect or absorb the infrared light, so walls behind them can shift or disappear.
- Clutter along the walls hides corners and skirting, and the scan then guesses where the wall is.
- Very large or open spaces push the sensor toward its range limit, and small errors add up across many metres.
- Moving too fast, or skipping a corner, leaves gaps that get filled in by estimation.
- Dim rooms give the camera less to work with. LiDAR itself works in the dark, but the camera half of the scan does not.
How to check a scanned plan
- Measure the longest wall with a tape or a laser meter and compare it with the plan.
- If it is off, correct it. After a CamPlan video scan you can enter the real length of a wall you measured and the whole plan rescales to match. In any plan you can also edit a wall's length directly.
- Spot-check a door width and one more wall in a different direction.
- For anything cut to size, like worktops, built-in furniture or glass, measure on site regardless of the plan.
Video scans and drawn plans
A video scan estimates distances from images rather than measuring them, so it is less precise than LiDAR, and the one-wall check above matters more. A plan drawn from your own tape measurements is as accurate as your measuring. For quotes and planning furniture, any of the three methods is fine once you have checked a reference wall. For the differences between them, see do you need LiDAR to scan a room.
FAQ
Is an iPhone LiDAR scan accurate enough for an architect?
For an existing-conditions plan and early design work, usually yes, especially after checking a reference wall. For construction drawings, architects normally verify critical dimensions on site.
Is LiDAR more accurate than a laser distance meter?
No. A good laser meter is accurate to a few millimetres on a single distance. LiDAR's advantage is speed: it captures the whole room at once instead of one measurement at a time.
Why is my scanned room slightly smaller or larger than my tape measurement?
Usually because of clutter or skirting boards hiding the true wall line, reflective surfaces, or a missed corner. Measure the affected wall and correct it in the plan.
Try CamPlan
Scan with LiDAR, film a short video or draw by hand, and get an editable 2D and 3D floor plan. Free to start on iPhone, iPad and Mac.
Download on the App StoreRelated posts
- Do you need LiDAR to scan a room?
Which iPhones and iPads have LiDAR, what a LiDAR room scan gives you, and how to make a floor plan on an iPhone without it.
- How to measure a room for flooring, paint and furniture
Measure a room by hand or with your iPhone: floor area for flooring, wall area for paint, and the extra material to order for waste.
- How to make a floor plan from a video
Film a short walkthrough on any iPhone or iPad and turn it into an editable floor plan with AI Video Scan: how to film it and how to check the result.